In printers, print quality can degrade for a variety of reasons. For example, in ink jet printers, nozzles that fire ink can dry out either through not being used over extended periods of time, or just in the course of normal operation. Some printers include automatic nozzle firing detection. For example, during a test cycle before printing, the printer can monitor ejection of ink into a spittoon in order to verify proper operation of each print nozzle. The information generated by automatic nozzle firing detection can be used to trigger a printhead recovery sequence or trigger a warning message to a user.
Many printers also allow a user to print out a print pattern than can aid users in visually diagnosing print quality. This is an especially useful feature for users who want to see the effect on print quality when one or more nozzles of a printhead are not operating properly. For a desktop printer with six hundred nozzles, a 20 centimeter by 2 centimeter space can be sufficient to produce a readable test pattern. For a twelve-color printer with more than fourteen thousand nozzles, a 20 centimeter by 20 centimeter space may be required to produce a readable test pattern. For a twelve-color printer with thirty to sixty thousand nozzles printer, a much larger area may be required to produce a readable test pattern.